Studies of patterns of genetic diversity, genetic structure and ecological data across geographical ranges of species allow us to test hypotheses about the evolutionary responses of organisms to fluctuations in habitat connectivity and availability. Here we present a study aiming to assess genetic diversity, population structure and breeding system across the geographical distribution of a subtropical epiphyte, Tillandsia aeranthos (Bromeliaceae), endemic to the Plata River basin (Pampa biome). Seven nuclear microsatellite markers were genotyped in 203 individuals from 13 localities across Brazil and Argentina and 14 plastid regions were sequenced for a subset of the individuals. Additionally, we performed controlled pollination experiments to discuss correlations between breeding system, genetic diversity and structure in the species. Nuclear diversity levels were high (H_E = 0.806, H_O = 0.745, allelic richness = 5.860) with no haplotype differentiation detected (c. 9 kpb sequenced). Bayesian assignment analysis, supported by principal coordinate analysis and analysis of molecular variance, show low genetic structure across the studied area (F_ST = 0.031, P < 0.001). Controlled pollination experiments indicated complete self-incompatibility in all localities analysed. Our results show effective gene flow maintaining low genetic structure between localities for T. aeranthos across an extensive area in the Pampa.

中文翻译：

---

高基因流在新热带附生植物（铁兰（Tillandsia aeranthos），凤梨科）中维持广泛的物种凝聚力

对跨物种地理范围的遗传多样性，遗传结构和生态数据模式的研究使我们能够检验有关生物对生境连通性和可用性波动的进化反应的假设。在这里，我们提出一项研究，旨在评估亚热带附生植物铁兰（Tillandsia aeranthos）地理分布的遗传多样性，种群结构和育种系统（凤梨科），普拉塔河流域特有的（潘帕生物群落）。在来自巴西和阿根廷的13个地区的203个个体中对7个核微卫星标记进行了基因分型，并对其中一部分个体的14个质体区进行了测序。此外，我们进行了受控授粉实验，以讨论繁殖系统，遗传多样性和物种结构之间的相关性。核多样性水平高（ħ _Ë = 0.806，ħ _Õ = 0.745，等位基因丰度= 5.860），无单倍型分化检测（Ç 9 KPB测序）。在主坐标分析和分子方差分析的支持下进行的贝叶斯赋值分析显示整个研究区域的遗传结构较低（F_ST = 0.031，P <0.001）。受控的授粉实验表明，在所分析的所有地方完全不相容。我们的研究结果表明有效的基因流在南美大草原的广阔区域内维持了不动产T. aeranthos的低遗传结构。